Within the last several years, methods that exploit molecular biology have led to major advances in the field of molecular diagnostics using labeled nucleic acid probes to detect specific DNA and RNA sequences for the early diagnosis of inherited human disease. Diseases such as cystic fibrosis, muscular dystrophy, sickle cell anemia, phenylketonuria, beta-thalassemia, hemophilia A, and inherited forms of breast cancer can be detected in this way. The objective of this project is to develop two non-radioactive DNA probes that employ electroactive labels for the detection and quantification of known base-sequence abnormalities in the patient's DNA. The probes will be short stretches of single strand DNA synthesized to be complementary to non-overlapping segments of a target DNA sequence. One probe will be labeled with horseradish peroxidase and the other with colloidal gold. When both of these probes bind to the target DNA the resulting sandwich hybrid will be detected. The expected result of Phase I is to prove the feasibility of the system to be a simple-to-use, low- cost system for rapidly detecting abnormal DNA sequences based on the use of DNA probes, suitable for use in hospitals, clinics or doctors offices for screening and detection of a variety of diseases and detection of PCR products. PROPOSED COMMERCIAL APPLICATION: The gene probe format and electrochemical detection system found to be most effective in Phase I will be developed for specific AndCare products for (1) investigation and detection of gene defects; and (2) detection of PCR products in genetic studies. Both will use the GeneCare logo to associate these products with our distinctive line of biosensors and monitors.